Geographical Limitations on Integral Collector Storage Collectors Due to Freezing

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Frederick S. Schollenberger ◽  
Frank Kreith ◽  
Jay Burch
Keyword(s):  
Cold Weather ◽  
Weather Data ◽  
Data Correlation ◽  
Climate Conditions ◽  
Active Systems ◽  
Water Heaters ◽  
Solar Water Heaters ◽  
Freeze Protection ◽  
The U.S

Passive integral collector storage (ICS) solar water heaters can potentially heat water at lower costs then active systems with freeze protection. However, ICS panels can freeze in cold weather. This study developed a model relating the freeze behavior to climate conditions, validated the model experimentally and then ran the model with long term U.S. weather data to delineate regions safe for the passive solar heaters. Both, a single- and a double-glazed tubular ICS panels were modeled and tested. It was found that freezing begins when the water in the supply/return lines freezes and initiates a pressure build up in the collector which can eventually burst the large collector tubes when the water inside freezes and expands. It was found that freezing can be delayed by installing heat tape over the supply/return lines. Using a model of the collector and TMY2 weather data, correlation maps were developed to show in which regions of the U.S. ICS panels with and without heat tapes can be installed safely.

scholarly journals Optimum Values of Tank Volume to Collector Area Ratios of Thermosyphon Solar Water Heaters for Libyan Families

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
M. J. R Abdunnabi
Keyword(s):  
Optimization Technique ◽  
Operating Conditions ◽  
Hot Water ◽  
Weather Data ◽  
Active System ◽  
Solar Water ◽  
Water Heaters ◽  
Temperature Ranges ◽  
Solar Water Heaters ◽  
Auxiliary Heater

Thermosyphon solar water heaters are the best choice to be utilized in residential sector to provide the required hot water in Libya. These systems are autonomy in operation and as a result require less maintenance and hence low operation and initial costs than active system. ln this paper, GenOpt optimization technique provided in TRNSYS simulation program is used for sizing Thermosyphon systems to obtain the optimum size (namely V/A ratio) of Thermosyphon system that suits Libyan families according to the weather and operating conditions of Tripoli. The typical hot water load pattern and quantity of the Libyan families are taken from a field study conducted on a number of solar system for a whole year. Whereas, the typical weather data are taken from five year measurements recorded at CSERS weather station. The results showed that the optimum storage tank volume to collector area ratio of Thermosyphon systems is between 49-60 Lit/m2 for the most common collector characteristics ratio (equation!!) and the auxiliary heater set point temperature ranges from (45-60C). 

A lesson learned from the long-term subsidy program for solar water heaters in Taiwan

2018 ◽  
Vol 41 ◽  
pp. 810-815 ◽  
Author(s):  
Keh-Chin Chang ◽  
Wei-Min Lin ◽  
Kung-Ming Chung
Keyword(s):  
Solar Water ◽  
Water Heaters ◽  
Subsidy Program ◽  
Solar Water Heaters

scholarly journals ANALYSIS OF ECOLOGICAL AND BIOLOGICAL FEATURES OF CASTANEA SATIVA MILL. IN NATURAL AND CLIMATE CONDITIONS OF THE CENTRAL BLACK EARTH REGION (ON THE EXAMPLE OF THE VORONEZH REGION)

2021 ◽  
Vol 11 (1) ◽  
pp. 24-35
Author(s):  
Svetlana Degtyareva ◽  
Valentina Dorofeeva ◽  
Valentina Shipilova
Keyword(s):  
Castanea Sativa ◽  
Cold Weather ◽  
Climate Conditions ◽  
Biological Features ◽  
Factors Influencing ◽  
Voronezh Region ◽  
Castanea Sativa Mill ◽  
The Stability ◽  
Species Ecology

Knowledge of species ecology and biology in general and characteristics of its acclimatization in a particular region are the basis for its successful selection. In this work, the authors present the results of long-term phenological observations of Castanea sativa Mill. since its planting (1967). Ecological and biological analysis has showed some discrepancies in the passage of phenophases. If the growth processes were not completed before the onset of the autumn-winter cold weather, then in recent years the leaf fall ends at the end of October, annual shoots lignify, growth and generative buds are formed. But, in general, it allows us to draw conclusions about the correspondence of the seasonal rhythms of development of the studied sowing chestnut as an introduced species to their local ecological-phytocenotic analogues. It was experimentally established that the fruits of the chestnut do not need pre-sowing treatment, because seed germination is high (70%). The groups of leading factors influencing the stability and development of the species as a whole (in the study area) have been identified. These are: lack of heat in summer, which affects the formation of fruits; short autumn period with high temperature drops, which limits the ripening of the shoots; different spring periods, contributing to the loss of hardening; unstable winter with sharp cold snaps and thaws, intensifying the nature of winter damage

scholarly journals Long-Term Durability of Cold Weather Concrete : Phase II

2021 ◽  
Author(s):  
Benjamin E. Watts ◽  
Danielle E. Kennedy ◽  
Ethan W. Thomas ◽  
Andrew P. Bernier ◽  
Jared I. Oren
Keyword(s):  
Room Temperature ◽  
Cold Weather ◽  
Chemical Admixtures ◽  
Rapid Setting ◽  
Petrographic Examination ◽  
Active Research ◽  
Freeze Protection ◽  
Very High ◽  
Recent Laboratory

Recent laboratory results confirm that it is possible to protect concrete from freezing solely using chemical admixtures and indicate that the amount of admixture required may be significantly less than previously recommended. Researchers have also verified that admixture-based freeze protection can produce concrete that is durable to winter exposure for a minimum of 20 years, through petrographic examination of core specimens obtained from past field demonstrations. Freeze protection for concrete using chemical admixtures alone has been an area of active research for 3 decades; however, the most recent methodology recommends very high addition rates of accelerating and corrosion inhibiting admixtures, which result in significant challenges, including slump loss, rapid setting, and potentially excessive temperature rise. As part of a laboratory study, researchers systematically varied the dosage of freeze protection admixtures used in concrete cured in a 23 °F environment. Preliminary findings indicate that a 50% reduction in admixture dose maintained adequate freeze protection and resulted in compressive strengths exceeding those of room-temperature controls at 7 and 28 days. The combination of improved handling, reduced cost, and verified durability associated with the use of admixtures for freeze protection makes a compelling case for broader adoption of this technique in winter operations

The Input-Output Model for Solar Water Heaters: Model Errors and Long-Term Performance Estimate

1990 ◽  
Vol 112 (3) ◽  
pp. 161-168
Author(s):  
L. Kadi ◽  
B. Bourges ◽  
J. Adnot
Keyword(s):  
Test Method ◽  
Model Errors ◽  
Input Output ◽  
Solar Water ◽  
Water Heaters ◽  
Performance Estimate ◽  
Solar Water Heaters ◽  
Long Term Performance ◽  
Term Performance

Based on the experimentally observed linear relationship between the daily collected energy and the daily insolation, the development of a test method for the performance rating of solar water heaters is studied using both an analytical modeling of the daily performance and detailed simulation. This analysis has shown the existence of a general linear correlation between daily performance and external conditions (daily irradiation, ambient temperature, main’s water temperature, and storage initial temperature). Two approaches appeared possible for the long-term performance estimate and, for its simplicity, the statistical one was chosen for the definition of the European test method for solar water heaters, also known as the input-output test method.

scholarly journals Generation of Synthetic Daily Weather for Climate Change Scenarios and Extreme Storm Intensification

2019 ◽  
Vol 9 (2) ◽  
pp. 1
Author(s):  
Jurgen Garbrecht ◽  
X. C. Zhang ◽  
David Brown ◽  
Phillip Busteed
Keyword(s):  
Climate Change ◽  
Weather Data ◽  
Climate Projections ◽  
Climate Change Scenarios ◽  
Generation Model ◽  
Traditional Role ◽  
Climate Conditions ◽  
Daily Weather ◽  
Daily Weather Data

Long-term simulations in watershed hydrology, soil and nutrient transport, and sustainability of agricultural production systems require long-term weather records that are often not available at the location of interest. Generation of synthetic daily weather data is a common approach to augment limited weather observations. Here a synthetic daily weather generation model (called SYNTOR) is described. SYNTOR fulfills the traditional role of generating alternative weather realizations that have statistical properties similar to those of the parent historical weather it is intended to simulate. In addition, it has the capability to simulate daily weather records for climate change scenarios and storm intensification due to climate change. The various model components are briefly summarized and an application is presented for semi-arid climate conditions in west-central Oklahoma. SYNTOR generated daily weather compared well with observed weather values. Climate change is simulated by adjusting weather generation parameters to reflect the changed mean monthly weather values of climate projections. Storm intensification is approximated by increasing the top 10 percentile of storm distribution by a predefined amount based on previous studies of trends in United States precipitation. Further evaluation of published storm intensification values and associated uncertainties and spatial variability is recommended.

Long term performance of evacuated tubular solar water heaters in Sydney, Australia

Solar Energy ◽  
1984 ◽  
Vol 32 (6) ◽  
pp. 785-791 ◽  
Author(s):  
G.L. Morrison ◽  
N.H. Tran ◽  
D.R. McKenzie ◽  
I.C. Onley ◽  
G.L. Harding ◽  
...  
Keyword(s):  
Solar Water ◽  
Water Heaters ◽  
Solar Water Heaters ◽  
Long Term Performance ◽  
Term Performance ◽  
Sydney Australia
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